ENVIRONMENTAL FACTORS’ INFLUENCE ON THE DIAMONDBACK MOTH (PLUTELLA XYLOSTELLA L.) POPULATION DYNAMICS ON CRUCIFEROUS CROPS

Abstract

The diamondback moth (Plutella xylostella L.) (Lepidoptera: Plutellidae) is one of the most severe pests for cruciferous crops. Its widespread distribution and the ability to submissive migration led to an unexpected enhancement in its population, thereby obscuring the control measures aimed at this phytophagous. The presented study sought to determine the expansion of diamondback moth in cruciferous crops (rapeseed, mustard) in two agroclimatic zones of Northern Kazakhstan (Zone I: moderately humid and warm; Zone II: slightly humid and moderately warm). Analysis of population dynamics ran for the long-term during 2012–2022 based on bioecological patterns of the diamondback moth and factors affecting them. Numerical variables of population density and abundance indices served as diagnostic predictors for characterizing the phase state of the pest in a given period and, therefore, recognizing the population dynamics pattern of the diamondback moth. Based on the results, the biological regularity of the stage inception of the phytophagous abundance dynamics does not always persevere, and variations occur with the sway of environmental factors. Hence, the abundance dynamics of diamondback moth depend upon the weather conditions of the previous and current year, as well as, on the accomplishment of the extent of chemical treatment and its regulations. The obtained data can be criteria for predicting the phase state of diamondback moth populations in the agroclimatic zones of northern Kazakhstan to justify and plan protective measures, as well as, to improve phytosanitary control.